Years of Failed Efforts to End Syrian Conflict

Since the start of Syria's war in 2011, several diplomatic initiatives have stumbled over the future of President Bashar al-Assad. Here is a recap:

- End of Arab solutions - In January 2012, two months after an initial bid to end the violence, leading Arab diplomats adopt a fresh plan that would transfer power from Assad to a coalition cabinet. The Damascus government rejects the proposal and vows to crush rebel movements.

- Geneva I, ambiguous formula -On June 30, 2012 in Geneva, global powers draw up a plan that would install a transition government, but which does not spell out what would happen to Assad.

Among those drafting the proposal are the five permanent members of the UN Security Council, Britain, China, France, Russia and the United States, along with representatives from the Arab League, Turkey and the European Union.

Members of the so-called Action Group for Syria differ over what the plan really means however, with the US saying that it paves the way to a "post-Assad" period. China and Russia, which are allies of Assad, insist it is up to Syrians to decide their future.

- Geneva II, no agreement -In January 2014, the first talks between Syrian opposition groups and the government are held in Geneva under the auspices of Russia and the US.

On February 15, UN mediator Lakhdar Brahimi calls an end to the talks after a second fruitless session, and resigns.

- Russian offensive/Vienna process -On October 30, 2015, a month after Russian forces launch an intervention to support Assad, several countries meet in Vienna to explore the chance of a political solution.

They include France, Russia and the US, and also, for the first time, Iran.

In November, a transition outline is drawn up but the question of Assad's future is still not resolved.

On February 27, 2016, a ceasefire is imposed by Russia and the United States.

But on April 22 the truce is shattered by the fierce bombardment of Aleppo by regime forces.

In March and April, three rounds of indirect talks take place in Geneva between Syrian rebels and the government under UN auspices. They are stymied by questions regarding a political transition, and ceasefire violations.

- Moscow, Ankara, Tehran take over -On August 9, Turkish President Recep Tayyip Erdogan meets with Russia's Vladimir Putin to cement closer ties between the two countries. Turkey backs some Syrian rebel groups and had shot down a Russian jet in late 2015.

Two weeks later, Turkey launches an operation in the northern Aleppo province to battle Islamic State jihadists and Kurdish militia.

On December 22, Syrian forces regain control of Aleppo with backing from Russia.

On December 29, Moscow announces a ceasefire between the government and rebels and a plan to hold peace talks sponsored also by Iran and Turkey, in Kazakhstan.

- Astana talks -On January 17, 2017, Russia says that talks between the government and rebels should lead to a consolidation of the ceasefire.

Most rebel groups agree to attend the Astana talks, with the exception of Ahrar al-Sham, which counts thousands of fighters in central and northern Syria.

On January 19, Assad calls on rebels to lay down their arms in exchange for an amnesty, but rules out any chance of a transition government or discussion of his departure.

On January 20, a Turkish official says it is no longer "realistic" to insist that Assad step down.